JPS6289773A - Optical coating composition - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Field of Application] The present invention relates to compositions for forming optical layers, particularly for use in the production of optical recording media.

BACKGROUND OF THE INVENTION In response to demands for better reliability and higher capacity data storage and retrieval systems, there has been active research and development of so-called φ optical disk recording systems. These systems use highly focused modulated beams of light, such as laser beams. This is directed into a recording layer that can absorb a substantial amount of light.

The heat thus generated causes chemical and/or physical changes in the light-absorbing material in the area hit by the highly focused laser beam and changes the optical properties of the affected area, e.g. transmissivity or reflectivity. Generate simultaneous changes.

For readout, the contrast between the amount of light transmitted or absorbed from the marked areas of the absorption layer and that from the unaffected v4 region is measured.

Examples of such recording systems are found throughout the literature and in many US patents such as tJ, S, 3,314,073.
No. 3,474.457. In recording data, a rotating disk with a light-absorbing recording layer is exposed to modulated radiation from a laser light source. This radiation passes through a modulator and suitable optics and a highly focused laser beam is directed onto the disk, which is caused by chemical and/or physical reaction of the light absorbing layer.
A series of very small marks (
series) form a set. Mark frequency (f r
eqer+cy ) is determined by the modulator input.

Using a laser beam with a focal point diameter of less than 1 μm, data can be stored at a density of 108 bits/cm2 or more.

The simplest optical disc media simply consist of a dimensionally stable solid substrate coated with a light absorbing material such as a metal layer. When the light-absorbing layer is exposed to coherent light, e.g. from a laser source, the light-absorbing material evaporates and/or becomes thermally degraded, forming a very small marked area, which overlaps with the nearby unmarked layer. exhibit different transmission or reflection. For example, S pong's U, S, 4,305.08
1 specification, and 3ell U, S, 4,270.1
A multilayer anti-reflection structure, such as that disclosed in US Pat. No. 3,326,000, improves the absorption of the laser beam, which also provides better read/write contrast than when using a single layer medium. Therefore, for the purpose of obtaining better output efficiency, sensitivity and readout response of the recording, it is preferable to use a multilayer anti-reflection structure.

There are two basic types of multilayer antireflection structures, one of which is essentially a two-layer structure and the other a three-layer structure.

In two-layer media, the substrate is coated with a very smooth, highly reflective material, such as aluminum, and on top is coated with a layer of a moderately light-absorbing material, preferably λ/4n thick. Here, λ is the wavelength of the recording light source, and n is the reflection coefficient of the light absorption layer. In three-layer media,
The base is very smooth and high anti-corrosion as well! A first layer of 1FJI material is coated on top of which a second layer of permeable material is coated. Over this transparent second layer is coated a third thin layer of strongly light-absorbing material. The combined thickness of these transparent and absorbent layers is preferably adjusted to approximately λ/4n. In both types of structures, tuning the thickness of a layer according to the light waves & the reflection coefficient of that layer minimizes the amount of light reflected from unmarked areas and from marked areas. The purpose is to maximize the amount of reflected light and thus create higher playback signal amplification. Details of the three types of disk configurations can be found in A, E, and Bel's computer[)esign, Jan 198
3, pp. 133-146 and the references cited therein. Especially 3ell and S
ponu's I E E E J o n al of
QuantumE Electronics, Vol.
, Q E -14, 197J3. pp, 487-495
checking ...

Of course, the terms two and three layers refer only to the basic optical layer and do not exclude the use of auxiliary layers.In particular, what is essential in most cases is that It has a polymer layer that also has an important function.(1
) The layer must be optically smooth to provide an optically adequate basis for the overlying reflective layer.

(2) The layer must have good adhesion to the underlying substrate and to the overlying reflective layer.

Furthermore, these properties must be sustained under all environmental conditions to which the media may be exposed when used and stored.

[Prior art] 4 4 i 'kstra~D 1
disclose a laser beam recording medium in which an energy absorbing recording layer is protected by a cured layer of LIV-curable lacquer as an adhesive layer and a layer of transparent resin thereon. There is. The lacquer is preferably a mixture of proton acrylic esters such as droxyalkyl or amyl alkyl acrylates. The overlying resin layer can be made of any of several types of transparent resins, including poly(methyl methacrylate).

In the laser single recording medium of this patent, the energy absorbing recording layer is protected by an overlying SiO2 transparent layer.

It is disclosed here that if the thickness of 5i02 is sufficient, it can move surface dirt and grime away from the focal surface of the laser beam.

In the laser beam recording media of the Loudlou et al. patent, the energy absorbing recording layer is coated with an underlying layer of poly(alkyl methacrylate) or fluorinated polyethylene.

U, S, 4 300 14 elljBell
In the optical recording medium of the et al. patent, the recording layer is comprised of adjacent transparent layers of organic or inorganic material of 1! protected.

U, S, 4 477 328 Broeks
This patent discloses a liquid coating for use on optical recording disks comprising a solution of a 7 acrylate or methacrylate and a photoinitiator with a viscosity of 1000-15000 cP. A preferred oligomer is molecule 11300
-1000. alkylene bis(
phenoxyalkyl acrylate) and alkylene-
Only bis(phenoxyalkyl methacrylate) is disclosed.

The Maer et al. MaVer patent discloses rotational coating of optical disk substrates with a composition comprising a mixture of an acrylate prepolymer, a triacrylate monomer, a monoacrylate monomer, a surfactant, and an initiator. . One composition is disclosed that includes only a high molecular weight acrylate oligomer, 2-ethylhexyl acrylate, a surfactant, and an initiator. Compositions using oligomers with molecules less than 1000 are not disclosed.

DETAILED DESCRIPTION OF THE INVENTION The present invention provides, in a first aspect, a liquid hydroxy-lower alkyl monoacrylate having dissolved therein an oligomer having at least 500 molecular ports, and c. 0.05-10% by weight photoinitiator.

wherein the liquid uncured solution has a viscosity of at least 10 cP and a surface tension at coating temperature of less than 35 dyn 7011, and the solid cured composition has a viscosity of at least 10 cP and a surface tension of less than 35 dyn 7011;
and a pencil hardness of at least 2B.

In a second aspect, the invention comprises: 1) applying a liquid layer of the coating composition described above to a substrate at a temperature such that the viscosity of the composition is 10-100 cP; and exposing the acrylic monomer to chemical radiation for a time sufficient to substantially completely photocure the acrylic monomer.

In a third aspect, the invention is directed to an optical recording medium comprising: 81 a dimensionally stable substrate; a layer of light-absorbing material; and an optical layer coated on Hb by the method described above. ing.

Unless the terms are applied to specifically named compounds, the terms "acrylic" and "acrylate" are used herein to refer to the acrylic (R2O-C-)H3 moiety and the methacrylic (R2C-C-) moiety. It is intended to include both.

[Structure of the invention] A, photocurable monomer U.S. Patent Application S, N filed concurrently with this application.

(PD-2151), it is disclosed that monomers suitable for making optical coating compositions must meet each of the following four criteria:

(1) not less than 4 carbon atoms in the ester group; (2) mutual solubility with the oligomer; (3) liquid at room temperature; and (4) monofunctionality.

Because the composition of the present invention does not contain volatile solvents and because the acrylic monohedron also acts as a dispersion medium for the oligomer and photoinitiator, the composition is preferably room temperature at any temperature at which it is coated. Since it must be liquid at I! The polymer must also be liquid at room temperature. All hydroxy-lower alkyl acrylates used herein are liquids at room temperature.

Despite the general criteria of molecular size regarding the number of carbon atoms of the monoacrylates of the application, very unexpectedly,
It has been found that even monofunctional acrylates having less than 4 carbon atoms are very useful as long as they are substituted with at least one hydroxy group. Therefore, suitable primary monofunctional acrylate intermediates are:

Contains:

Hydroxymethyl acrylate Hydroxymethyl methacrylate 1- and droxyethyl acrylate 2-hydroxyethyl acrylate (HEA) 1- and droxyethyl methacrylate 2-hydroxyethyl methacrylate (HEMA) 1-hydroxypropyl acrylate 2-hydroxypropyl acrylate (2-HPA) 3-hydroxy Propyl acrylate 1-hydroxyethyl methacrylate 2-hydroxypropyl methacrylate 3-hydroxypropyl methacrylate 1
-Hydroxyisopropyl acrylate 2-hydroxyisopropyl acrylate 1-hydroxyisopropyl methacrylate 2-hydroxyisopropyl methacrylate dihydroxymethyl acrylate dihydroxymethyl methacrylate 1,2-dihydroxyethyl acrylate 1,2-dihydroxyethyl methacrylate 1-methyl-2,2
-dihydroxyethyl acrylate 1-methyl-2,2-dihydroxyethyl methacrylate 1-hydroxymethyl-2-hydroxyethyl acrylate 1-hydroxymethyl-2-hydroxyethyl methacrylate 2,2-dihydroxyethyl acrylate 2,2-dihydroxyethyl methacrylate 1-methyl-1,2
-dihydroxyethyl acrylate 1-methyl-1,2-dihydroxyethyl methacrylate 3.3-dihydroxypropyl acrylate 3.3-
Dihydroxypropyl methacrylate 1,3-dihydroxypropyl acrylate 1,3-
Dihydroxypropyl methacrylate 2.2-dihydroxypropyl acrylate 2.2-dihydroxypropyl methacrylate 1.2-dihydroxypropyl acrylate 1.2-
Dihydroxypropyl methacrylate 1.1-Dihydroxypropyl acrylate 1.1-
Dihydroxypropyl methacrylate All monolayers listed above are liquid at room temperature and are compatible with the oligomer and initiator components of the compositions of the present invention.

As pointed out in the above-mentioned application, multifunctional acrylates are not suitable except in very sensitive applications because the photocured monomers cause excessive shrinkage and reduce adhesion. do not have. Although unsuitable as main monomers, polyfunctional acrylate monomers and solid monofunctional acrylate monomers can be used as a total monolayer component, as long as they meet the aforementioned conditions. up to about 10% by weight can be used. However, it is preferred not to use more than about 15% by weight.

B. Oligomer The oligomer component of the composition is the main material for controlling the physical properties of the composition. In particular, this is a means for adjusting the viscosity of the coating composition and for adjusting the hardness and other physical properties of the photocured layer.

Therefore, as long as the oligomer can be completely dissolved in the acrylic unit, the criteria for its chemical composition are not narrow. Thus polyacrylates, epoxy resins, polyurethanes, aminoblast resins and phenolic resins can all be used as oligomeric components of the compositions of the invention. As used herein, "oligomer" refers to a linear or non-linear polymer having from 2 to 10 repeating units.

If an acrylate oligomer is used, it can be monofunctional or polyfunctional, so it
It can be an oligomer of any of the monofunctional acrylate ψ-mers listed above, or it can be an oligomer of acrylate monomers that do not meet the five conditions listed above.

For example, monolayer bodies that do not meet these conditions are as follows.

1.4-butanediol dimethacrylate, 1.6-
Hexanediol diacrylate, 1,6-hexanediol dimethacrylate, n-lauryl acrylate, n-lauryl methacrylate, methyl methacrylate, 2-methoxymethylethyl acrylate, neopentyl glycol dimethacrylate, octadecyl acrylate, octadecyl methacrylate, polyethylene glycol dimethacrylate , tetrahydrofurfural acrylate, trimethylolpropane triacrylate, tripropylene glycol
Diacrylate, 1.5-bentanediol diacrylate, N,N-diethylaminoethyl acrylate, ethylene glycol diacrylate, 1,4-butanediol diacrylate, diethylene glycol diacrylate, 1,3-propanediol diacrylate, decamethylene glycol Diacrylate, decamethylene glycol dimethacrylate, 1
．． 4-cyclohexanediol diacrylate, 2.2-dimethylol propane diacrylate, glycerol diacrylate, glycerol triacrylate, pentaerythritol triacrylate, 2.2-di(p-hydroxyphenyl)-propane diacrylate, pentaerythritol tetraacrylate, 2.2-
Di(p-hydroxyphenyl)-propane dimethacrylate, triethylene glycol diacrylate polyoxyethyl-2,2-di(p-hydroxyphenyl)-propane dimethacrylate.

Di(3-methacryloxy-2) of bisphenol A
-hydroxypropyl) ether, bisphenol-A
di-(2-methacryloxyethyl) ether, di-(3-acryloxy-2-
hydroxypropyl) ether, di(2-acryloxyethyl) ether to bisphenol, di(3-methacryloxy-2-hydroxypropyl) ether of tetrachloro-bisphenol-A, di(2-hydroxypropyl) ether of tetrachloro-bisphenol-A, -methacryloxyethyl) ether, di(3-methacryloxy-2-hydroxypropyl) ether of tetrabromo-bisphenol A, di(2-methacryloxyethyl) ether of tetrabromo-bisphenol A, di(methacryloxyethyl) ether of 1,4-butanediol (3-methacryloxy-2-hydroxypropyl) ether, di(3-methacryloxy-2-hydroxypropyl) ether of diphenolic acid, triethylene glycol dimethacrylate, polyoxypropyltrimethylol propane triacrylate (462) ethylene Glycol Diacrylate Any Butylene
Glycol Dimethacrylic 1-1-11.3-propanediol Dimethacrylate, 1.2.4-butanediol Trimethacrylate, 2.2.4-trimethyl-1,3-bentanediol
Dimethacrylate, pentaerythritol trimethacrylate, 1-phenyl ethylene-1,2-dimethacrylate 1-1., pentaerythritol tetramethacrylate, trimethylol propane trimethacrylate, and 1,5-bentanediol dimethacrylate.

Epoxy resins that can be used in the present compositions include those having the formula below.

where b is a positive integer of about 1 to 4.

Preferably the epoxy resin is a polymerization product of shrimp chlorohydrin and bisphenol-A. In a preferred epoxy resin, R2 in the above formula is as follows.

Typical of these preferred epoxy resins is 3hellC
chemical company, houston,
E with an equivalent weight of about 185-192 produced in TX
DOn828, and The Dow Chem
ical CompanyM 1dland, M I
DE having an equivalent weight of about 182-190f7) produced in
It is R331. Weight is the number of grams of resin containing the most epoxide per weight.

Epoxy novolac resins that can be used in the composition have the formula:

where d is a positive integer of about 1-2. Preferred epoxy novolac resins are DE having an average 1 m of d of 0.2.
N431, (DEN438 with an average value of j of 1.6, and DEN439 with an average value of d of 1°8. These resins are also manufactured by The DowChemtcal Coll1
Manufactured by pany.

A wide variety of liquid crosslinking resins can be used as the oligomeric component for the present invention, including thermosetting resins such as aminoplast resins, phenolic resins, blocked polyisocyanates, and masked isocyanates.

The aminoblast resins used may be alkylated methylol melamine resins, alkylated methylol ureas, and similar compounds.

Products obtained from the reaction of alcohol and formaldehyde with melamine, urea or benzoguanamine are the most common and are preferred here. However, condensation products of other amines and amides can also be used. for example,
Aldehydic combinations of triazines, diazines, triazoles, guanadines, guanamines, and alkyl and aryl substituted derivatives of these compounds, including alkyl and aryl substituted ureas and alkyl and aryl substituted melamines. Examples of such compounds are N,N'-dimethylurea, benzourea, dicyandiamide, formguanamine, acetoguanamine, amerine, 2-chloro-4°6-diami2 1.3.
5-triazine, 6-methyl-2,4-diamino-1,
3,5-triazine, 3,5-diaminotriazole,
Triaminopyrimidine, 2-mercapto-4,6-diamitubirimidine, 3.4.6-tri(ethylamino)-
1,3,5-triazine, etc.

The aldehyde used is most often formaldehyde, but other similar condensation products can be prepared from other aldehydes such as acetaldehyde, crotonaldehyde, acrolein, benzaldehyde, furfural, glycols, and the like.

Aminoplast resins contain methylol or similar alkylol groups, and often at least a portion of these alkylol groups are etherified by reaction with an alcohol to provide a 1mg soluble resin.

Any monohydric alcohol can be used for this purpose, including alcohols such as methanol, ethanol, propatool, butanol, pentanol, hexanol, heptatool and others, and benzyl alcohol and other aromatic Group alcohols, and cyclic alcohols such as cyclohexanol, monoethers of glycols such as cellosolve and carpitol, and others [including alcohols such as 3-chloropropanol and butoxetanol]. Preferred aminoblast resins are substantially etherified with methanol or butanol.

Phenolic resins that can be used here are produced by condensation of aldehydes and phenols. The most used aldehyde is formaldehyde, but other aldehydes such as acetaldehyde can also be used. Methylene releasing and aldehyde releasing agents such as paraformaldehyde and hexamethylenetetraamine can optionally be used as aldehyde agents.

A variety of phenols can be used. for example,
The phenol used is phenol itself, cresol, or M-substituted phenol, in which the hydrogen of the aromatic ring is substituted with a hydrocarbon group having a linear, branched, or ring structure. Mixtures of phenols are also often used. Examples of phenols used for the preparation of these resins include p-phenyl-phenol, p-tert-butylphenol, p-tert-amylphenol, cyclobenthylphenol, and unsaturated hydrocarbon-substituted phenols. Included are phenols, such as monobutenylphenols containing a butenyl group in the ortho, meta or para position, where the double bond occurs at various positions in the hydrocarbon. A common common phenolic resin is phenol formaldehyde.

Particularly preferred types of phenolic resins are alkyl ethers of hepnotic, di- and trimethylolphenols. Various forms of these resins are described in U.S. Pat.
79.329@, No. 2.579.330, No. 2,57
9,331@, No. 2,598.406, No. 2,606
, No. 929, No. 2.606.935 and No. 2.82.
No. 5°712. These substances are manufactured by General Electric Co., 5
chenectady.

Sold under the trademark M ety+on by New York, NY.

Blocked organic polyisocyanates can be used here as oligomeric components.

Conventional organic polyisoanates such as those described above that are blocked with volatile alcohols, ε-caprolactam, ketoxime, etc. and are deblocked at temperatures of 100° C. or higher may also be used.

These curing agents are well known in the art.

Masked polyisocyanates can also be used as hardeners. These masked polyisocyanates, as known in the art, are not derived from isocyanates, but produce isocyanates upon heating at elevated temperatures.

Examples of useful masked polyisocyanates include diamine imides, [e.g. Iht
) that generate free radicals when exposed to

These are substituted or unsubstituted polyquinones, compounds having two ring carbon atoms in a conjugated carbocyclic system, such as 9.10-anthraquinone, 2-
Methylanthraquinone, 2-ethylanthraquinone, 2
-Tertiary-butylanthraquinone, octamethylanthraquinone, 1,4-naphthoquinone, 9.10-phenanthrenequinone, benz(a) anthracene-7,12-dione, 2,3-naphthacene-5,12-dione, 2- Methyl-1,4-naphthoquinone, 1,4-dimethylanthraquinone, 2.3-dimethylanthraquinone, 2-phenylanthraquinone, 2.3=diphenylanthraquinone, retinquinone, 7°8.9.10-tetrahydronaphthacene-5゜12-dione, and 1. ,．． 2.3.
4-tetrahydrobenz(a) anthracene-7,12
-Zeon. Other useful photoinitiators, some of which may be thermally active at temperatures as low as 85° C., are disclosed in U.S. Pat. , vivaloin, acyloin ethers such as benzoin methyl and ethyl ethers; α-hydrocarbon-substituted aromatic acyloins, including α-methylbenzoin, α-allylbenzoin, and α-phenylbenzoin. As an initiator,
U.S. Patent No. 2.850,445, No. 2,875°04
7@, No. 3,097,096, No. 3.074.974
No. 3.097,097 and No. 3.145.10
4, and U.S. Pat. Nos. 3.427161 and 3.479.185.
No. 3,549.367,
Phenazine, oxazine, and quinone class dyes, including leuco dyes with hydrogen donors, M 1chle
r ketones, benzophenone, 2.4.5-triphenylimidazoyl dimer, and mixtures thereof can be used. Useful in conjunction with photoinitiators and photoinhibitors are the sensitizers disclosed in U.S. Pat. No. 4,162,162. The photoinitiator or photoinitiation system is present at a maximum of 0.05 to 101% based on the total weight of the dry photopolymerizable layer.

E. Formulation In formulating the coating compositions of the present invention, the order of mixing is not critical. Generally, the easiest to prescribe is
The viscous liquid or soft solid oligomer and the photoinitiator, usually in a solvent, are added to the liquid monomer and stirred well so that all ingredients are in complete solution. This is the method used to make each coating composition shown in the examples.

As indicated above, it is important that the viscosity of the coating composition be suitable for the coating method being applied. If the composition is applied to a substrate by spin coating, the viscosity of the solution should be between 10 and 100 centiboise (cp). However, if the composition is applied in other ways, the viscosity can be even higher. For example, if the composition is applied by curtain coating, the viscosity can be as high as 3000 cP. The viscosity of the coating composition can be adjusted by varying the relative amounts of monolayer and oligomer. The amount of oligomer may be as low as about 1% by weight of the composition when using low viscosity coating methods. However, for high viscosity coating processes it may be as high as about 501% by weight. The photoinitiation system does not significantly affect solution viscosity.

Another important property of the liquid coating composition of the present invention is its surface tension, which must be less than 30 dyn 7 cm to obtain adequate coverage of the substrate by coating. In many instances, the solution of monolayer, oligomer, and initiator will have a suitable surface tension. However, if the solution has too high a surface tension, this can be lowered by adding small amounts of soluble nonionic surfactants. It has been found that oligomers of the fluorinated glycol type, such as oligomers of fluorinated acrylate esters, are most suitable for this purpose. However, many others can be used as well. Even if all the aforementioned monomer criteria are carefully monitored, it is still necessary to formulate the composition to ensure that the cured composition has a degree of at least 2B.

The reason for this is that if the cured composition is softer than 2B,
This is because the adhesion to the substrate is poor.

The compositions of the invention, in exceptional cases, contain finely divided and dispersed solids, such as polymeric solids. This is only if the reflection coefficient of the solids matches that of the hardened matrix in which they are dispersed.

Such particles must however be very small, on the order of 100 Å or less. Inclusion of such materials is effective to further reduce shrinkage of the coating.

F, Pier 110L In the examples, the following test method was used.

1.1 1iiLL: Transfer 1.2 ml of substance to a Wellsbrook field model adapted to a constant humidity water bath.
RVT Ser, No. 27814v Put into micro viscometer. All measurements are carried out at 25°C.

After a 1 minute temperature equilibration period, three viscosity readings are recorded at 1 minute intervals. The method was repeated for two more 1.2 mls, taking a total of 9 readings. All readings were taken at 1100RP.

Material viscosity is reported as the average of 9 readings.

2LL2L: 8.0 ml of substance
-/L, Brookfield Model LVTD Ser, No. 7 Dubtor” LV axis and conditioned with Endocal Model RTE-9DD refrigerated circulation bath.

Place in AO1770 digital viscometer. All measurements are 2
Perform at 5°C. After a 3 minute temperature equilibration period, each axis speed is:
At 60.30.12.12.30.60 RPM,
Record a single viscosity record.

This method is repeated for another 8.0 ml sample or 12 readings. Material viscosity is reported as an average of 12 runs.

2. Filter the batch of WUULL material through sequentially arranged nominal 0.1 μm and 0.2 times m absolute polypropylene filters. The filter is Membra*a,
Inc., Pleasanton, CA
94566 cartridge type. Pressure≦
5 psi is required for filtration pressure.

3. Dispense the material onto an 8" x 12" double weight window frame glass using an 811 doctor blade (4" wide).
rised)LIVfi(~6 ft/min:~6j/
am"). The speed of light is expressed as the number of UV passes required for the sample to be completely cured.

The membrane is carefully peeled from the glass surface, cut into ~2" x 2" pieces, and placed in a PerkinElmer Model 330 spectrometer for determination of percent transmission. Percent transmission is recorded at 632.8 nm, 780 nm, and 830 nm. Six measurements are recorded at each wavelength. The membrane is removed and reinserted into the membrane compartment between each measurement. The instrument is zeroed before each insertion of a membrane sample. %T is read out on a digital display. The percentage transmission at each wavelength is reported as the average of six measurements.

4. UTLIL Pour approximately 50 ml of material into a 4 oz clear straight shoulder glass jar for use in surface tension measurements. Six measurements are taken at air temperature according to the instrument operating instructions for a Fisher Model 21 surf stencil.

Surface tension (dyn/cm) is reported as the average of 6 measurements.

5. Fill a percent 111 path length quartz crystal spectrometer cell with material and set it at 340rv.
into the sample compartment of a zeroed PerkinElmer Model 330 (absorption mode). empty la
Place m cells in the control compartment. The optical density (OD) of the material is read out on a digital display. The optical density at 350 nm is directly proportional to the percent photoinitiator.

-Kai 1--r acure 651 3.195 2.68 2.940 2.46 6.1 set 111 The coefficient of reflection of the solution and film is the Fischer-Abe reflection cooled to 20°C using a temperature-controlled water bath. Measure according to the instructions given on the meter.

7,! LUL! L In this test, several pencil cores with increasing hardness values are
A certain cram is pressed against the coated surface in a predetermined manner until the surface is scratched. Surface hardness is determined by the hardest pencil grade that did not scratch the surface.

The pencil cores are listed below from softest to hardest. 6B, 5B, 4B, 3B, 2B, B1HB%F
, H, 2H13H, 4H15H.

6H, 7H, 8H, 9H.

The test begins using a Q ardco pencil hardness gauge and the hardest pencil. Grasp the holder firmly and lower the end of the tube onto the test surface. Rotate the selected pencil until it is closest to the operator and tilt the assembly down until the center point and tube end contact the surface at the same time. This defines the correct center angle of 45° to the surface. Push the gauge forward (and release) approximately 1.5 inches.

Observe the pencil track. Sufficient pressure must continue to be applied until it cuts or mars the membrane or breaks the sharp corners of the heart. (If neither cracking nor cracking is observed, repeat the test applying greater pressure until a clear observation is made. If the hardest core crash occurs, the membrane is so hard that it limits the measurement range of the test. If scratching or marring of the membrane occurs, proceed to testing with the next softer grade pencil until a test core is found that crashes without damaging the membrane. This is the pencil hardness of the membrane.

In the following examples, the numbers and abbreviations listed refer to the specific appropriate materials as described below.

A, Epoxy Acrylic Evoxy) Oligomer The following numbers refer to Ce1rad oligomers.

:3201.3500.3600.3700゜3701
．． 3702.3703° The following numbers refer to Ce1rad oligomers.

:6700゜C2 1st run
1 Gomer The following number refers to urethane oligomer.

:UV783,. The next number refers to the Ce+raa oligomer.

: 1700.7100°D, LiLIL adhesive F C-430F In the Iuorad F C-430 example, the following quality indication is flexible.
property), adhesion, and surface roughness (texture).
re ) used for measurements.

Flexibility: 1 Suppleness 2 Medium supple 3 Moderately brittle 4. Fragile Adhesion: 1 Poor 2 Medium 3 Good 4. Excellent No surface roughness 1 a little 2. Some amount 3. Significant / crack example Medicine” 2221- Several sets of compositions were made and tested in the manner described above.

In particular, these sets clearly demonstrate the effectiveness of hydroxy-lower alkyl acrylates with different oligomeric materials at different temperatures.

-111- Orgomer type 1-19
Epoxy 20-21 Acrylate 22-27
Data for coatings made from the urethane are shown in Table 1 below.

Specifications, Nojo 11F (Inner-r: No History) - Maoya 1
% --- Per ball % --- Photoinitiator - Ball amount % 3.8 3.8
3.8 Passage number for curing 2
2 2 Meiyo 1 sho of pure rock (no change in content twisted Ichiban 19 45 32 power Eeg group captive monomer 1 -Composition HEMA HEMA-
Weight% 57.7 76.9 Monomer 2 - Composition -- 1% by weight -- Ligomer 1 - Composition 3701 3702 - Weight% 38.5 19.2 Oligomer 2 - Composition -- -I! f amount % -- Photoinitiator -- Weight % 3.8 3.8 Surfactant -- Composition -- Single layer! −%
--Surface tension, dyn/cm -38,4 Surface passing number for Ol hardening 12 Ming IF purification:! (No change in content) ■-67 22i Engineering Eda Target Group Monomer 1 -Composition HEMA HEMA-
Mo4'% 76.9 71.0 Monomer 2 - Composition - - Weight; 1:% - Oligomer 1 - Composition 3703 3201 -
Weight% 19.2 26.5 Oligomer 2 -Composition--Single weight ¥%--Photoinitiator -weight h1-% 3.8 2.
5-world 1n1 activator - Composition - 1% by weight
-- Surface tension, dyn/Cm 38.5 38.4
Passage number for surface 11 hardening 2211JJzf! rlJy＞
i4+,! 7F in fC<JESL)LL3
8 9 Uniforce Egg Target Monomer l -Composition HEA) iE
A - Weight % 71.0 65.8 Monomer 2 - Composition - 1 weight % - Ligomer 1 - Composition 3201 3201 - Ball μ
% 26.5 32.0 Oligomer 2 - Composition - - Tunpu% - Photoinitiator - Tosei% 2.5 2.2 Surfactant - Composition - 1% by weight
-- Surface roughness 0 0 Passage number for curing 12 squares - Koichito
to tt Unii Egg Aiming Seven Tsuma-1-Composition HEA HEA~jT
(jj % 65.6 65.0 Seven Tsuma-2~
Composition -- Single layer r11°% -- Oligomer 1 - Composition 3201 3201-ton: -% 31.9 31.6 Oligomer 2 - Composition - Parlon-5T
i::j,% 1.0 photoinitiator
-Tunj,'L% 2.5 2.5 Surfactant -Composition--1% by weight--Surface tension, dyn/cm -Cured solid coating hardness 2B<3B surface roughness
1 Passage number for curing lV! LUL3
12 13 - % overlap -- % single - Photoinitiator - % overlap 2,5 2.5 Surface tension, dye/cm - Passage number for curing 1 1■=
14 15 HEA HEA-I Composition 1 (EA HEA-I
TI: % 78.3 76.9 Seven months-2-It
Or -- Single ball - 1% -- Sailigomer 1 - Composition 3703 3600 - Top % 19.2 19.2 Oligomer 2 - Composition -- Single ball % -- Photoinitiator - Top % 2.5 2 .5 Surfactant - Composition - 1% by weight
-- Surface tension, dyn/am -- Cured solid coating hardness Hes H
Flexibility 0 1 Adhesion 24 Surface roughness
33 Passage number for curing
11 Meiryo 1 engraving (no change in content) I! LiL3 16 17 Uni-2-Eda Group Seven Tsuma-1-Composition HEA REA? 2% 76.9 76.9 Monomer 2 - Composition -- 1% by weight -- Ligomer 1 - Composition 3700 3600 - % by weight 19.2 19.2 Oligomer 2 - Composition -- 1% by weight -- Photoinitiator - Tunpu % 2.5 2.5 Surfactant - Composition - FC-430 - Top % 1.0 Surface tension, dyn/am - Surface roughness
Passage number for 30 curing
11 fields, 18 19
UNIEZ composition monomer l -Composition HEA 2-HP
A-Ton t% 64.1 78.0 Nanatsuma-2-Composition HDODA-Ichimozuke%
16.7 - Oligomer l -Composition 3600 3600-
Ton t-% L6.0 19.5 Oligomer 2 -Composition--Single layer! li-% -- Photoinitiator - Polymerization % 2.1 2.5 Surfactant - Composition FC-430-Single j 7%
0.8 - *1.6-hesandiol diacrylate 4LL32
0 2 L 22YuhitaNiseIlNanatsuma-1-Composition HEMA HEA
HEA-% 76.9 76.9 76.
9 Monomer 2 - Composition --- 1% by weight
--- Sailigoma-1-Composition 6700 6700
UV893-weight% 19.2 19.2 19
．． 2 Oligomer 2 - Composition --- Performance%
--- Photoinitiator -Tokyo% 3.8 2.5
3.8 Field 1h1 activator - Composition --
--- Weight % --- Surface tension, dyn/cm --- Flexibility IO adhesion
4 4 1 Surface l 30 Passage number for curing 2 1
5 detailed fortune telling (no change in i-mail) -Tunxing% 76.9 76.9 Monomer 2 -Composition--Heavy-
−− Oligo? -1-group #t, UV783 1700
7100-ton % 19.2 19
．． 2 Oligomer 2 - Composition --- Single %
--- Photoinitiator - Clear% 3.8 3.8
3.8 Surfactant - Composition ----
Ton %---Surface tension, ciyn,'cm---Passage number for curing 3 3 2 examples 1st 9 26 27-wt%
82. G 82.0 Monomer 2 - Composition -- 1@, M% -- Oligomer 1 - Composition 7100 1700 - Weight % 15.5 15.5 Oligomer 2 - Composition -- 1% by weight -- Photoinitiator - Heavy %3.8 2.5Surface tension, dyn/Cm --Surface roughness
11 iM number for curing
11 Examples 1-19 all demonstrated excellent adhesion of compositions using hydroxy-lower alkyl acrylates with epoxy oligomers. Similarly, Examples 20 and 21 demonstrated excellent adhesion of compositions using hydroxy-lower alkyl acrylates with acrylate oligomers. Examples 22 and 23, where the oligomer was urethane, did not exhibit good adhesion because the cured coating was too soft. However, Examples 24-27 using HEMA as a monomer,
It showed very good hardness and excellent adhesion.

LLfh Heni 1 Product Name Celrad Product Acrylated Oligomer Manufacturer Celanese COrD, NeV
Y ork, N YProduct name Fluorad (F Iu
orad) Product Fluorinated Acrylate Ester Oligomer Manufacturer M 1nnnesota M ining
andM anuracturir+g C01+1
1) an'/S t, PaulJ4 N product name
U V (Urithane) Product Acrylated Urethane Oligomer Manufacturer Th1okol Carp, Danvers
, MA applicant's representative Patent attorney Takehiko Suzue - ``-Continued Neyama + 1'Mi; 12 (Method) % Formula % 2. Name of invention Optical coating composition 3. Relationship with person performing sleeve IF/11 patents Applicant name: I-Ken I Dupont Do-Ken Nemours Bank & Company 4, Agent address: UBE Building 5, 3-7-2 Kasumigaseki, Chiyoda-ku, Tokyo, 11+1 of the amendment order September 30, 1986 [6] The image of correction

Claims (1)

Claims: (1) An optical coating composition comprising: a. a liquid hydroxy-lower alkyl monoacrylate having dissolved therein; an oligomer having a molecular weight of at least 500; and c. 05-10% by weight of a photoinitiator system, the liquid uncured solution having at least 10% by weight at the coating temperature.
An optical coating composition having a viscosity of cP and a surface tension of less than 36 dyn/cm, wherein the solid cured composition has a transmission of at least 88% to light at a wavelength of 488-830 nm. 2. The composition of claim 1, wherein the monoacrylate is selected from 2-hydroxyethyl acrylate, 2-hydroxyethyl methacrylate, and mixtures thereof. (3) The composition according to claim 1, wherein the oligomer is an acrylated epoxy resin. (4) The composition according to claim 1, wherein a nonionic surfactant is dissolved therein. (5) The composition according to claim 4, wherein the surfactant is a fluorinated acrylate ester oligomer. (6) i. Applying a liquid layer of the coating composition of claim 1 to a substrate at a temperature such that the viscosity of the composition is at least 10 cP; ii. A method of coating a substrate with an optical layer comprising exposing the acrylate to chemical radiation for a period of time sufficient to substantially completely photocure the acrylate. 7. The method of claim 6, wherein the liquid layer has a viscosity of 10-100 cP and is applied by spin coating. (8) An optical recording medium comprising: a. a dimensionally stable substrate; b. a layer of light-absorbing material; and c. an optical layer coated on layer b by the method of claim 6. . 9. The medium of claim 8, wherein the light absorbing layer is a thin layer of polymeric dye supported on a layer of polymer coated on aluminum. 10. The medium of claim 9, wherein the polymeric dye is supported on a layer of polymer coated on aluminum.